Biomaterials-aided mandibular reconstruction using in vivo bioreactors

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Surgical Innovation

Background:

• Large mandibular defects pose significant reconstruction challenges due to anatomical complexity and tissue limitations.
• Current methods often require autografts or allografts, which have associated morbidities and limitations.
• There is a need for advanced techniques to generate patient-specific, vascularized bone for defect repair.

Purpose of the Study:

• To evaluate the efficacy of a 3D-printed in vivo bioreactor strategy for generating autologous vascularized bone for mandibular reconstruction.
• To assess the feasibility of using biomaterial-based space maintenance in conjunction with in vivo bioreactors for defect repair.
• To translate this regenerative approach for large mandibular defects in a clinically relevant large animal model.

Main Methods:

• Fabrication of 3D-printed in vivo bioreactors designed to interface with rib periosteum.
• Implantation of bioreactors into large mandibular defects in sheep, utilizing biomaterial space maintenance.
• Evaluation of generated bone tissue and repaired mandibles using radiographic, histological, mechanical, and biomolecular analyses.

Main Results:

• Successful generation of autologous vascularized bony tissue within the in vivo bioreactors.
• Significant bone regeneration and successful reconstruction of large superior marginal mandibular defects in 83% of sheep.
• Histological and radiographic evidence confirmed mature bone formation and integration within the defect site.

Conclusions:

• The in vivo bioreactor strategy, combined with biomaterial-based space maintenance, is a viable method for regenerating large, patient-specific vascularized bone for mandibular reconstruction.
• This approach avoids the need for exogenous cells or growth factors, utilizing the patient's own regenerative capacity.
• The use of clinically available biomaterials facilitates rapid translation to human clinical applications for improved patient outcomes.